Fibronectin Adsorption on Biodegradable Polyester Surfaces: A Comparative AFM and Quantitative Study

Fibronectin is an important extracellular matrix glycoprotein that plays a key role in regulating cell behavior, including cell adhesion, migration, and proliferation. For this reason, preconditioning of biomaterials with fibronectin is commonly used to enhance cellular responses. Nevertheless, protein‐material interactions constitute a complex physicochemical phenomenon that strongly depends on the characteristics of the supporting substrate. In this work, fibronectin adsorption was studied on different polyester‐based supports widely used in biomedical applications (polylactic acid ‐PLA‐, poly (ε‐caprolactone) ‐PCL‐, a 1:1 blend of PLA and PCL ‐PLAPCL‐, and poly (lactic‐co‐glycolic acid) ‐PLGA‐). This direct comparison among commonly used biodegradable polyesters under identical adsorption and characterization conditions provides a coherent framework for assessing substrate‐dependent differences in fibronectin adsorption. Qualitative and quantitative analyses were performed after immersing the samples in fibronectin solutions at two concentrations (5 and 20 μg/mL). According to the results, fibronectin adopts a globular conformation upon adsorption onto the polymer surfaces. A higher affinity was observed for PLA and PLGA, where a greater amount of adsorbed fibronectin was detected. This behavior correlates with the hydrophilicity of the materials, as determined by surface tension measurements. Furthermore, materials conditioned with 20 μg/mL fibronectin exhibited a higher amount of adsorbed protein compared to those conditioned with 5 μg/mL.